On 9.2.1943, two engineers - F.F.Gorodkov and A.I.Starodubcev - sent a letter to J.V.Stalin directly, describing a new very fast armored vehicle. Both engineers worked at the Factory No.200 in Chelyabinsk, which produced the hulls for KV series, IS series and other vehicles produced in the city industrial complex, aptly nicknamed "Tankograd" ("tank city"). Therefore, it's not surprising that it was the KV design that made the basis for the new tank proposal. As with many other amateurish Russian war projects, this design was also a product of patriotic zeal rather than rational engineering。The vehicle was not supposed to be THAT light (25 tons, as the name suggests), but it did fit in the army requirements for a light tank, brought by the army in mid 1943. It was projected with a 47mm gun, but given the size of the turret, a 76mm ZIS-5 and other guns would fit in quite fine. The T-50 was only 10cm shorter than the MT-25. Note how the suspension was projected with interwoven wheels (like the late German vehicles had). It's unlikely the two engineers had access to a Tiger at that point, so it's assumed they were influenced by the German halftracks. The projected speed was to be 40-45 km/h on average, but the maximum speed would be 100 km/h.

The reason the T-50-2 is going to be replaced is that the T-50-2 doesn't behave as the real life original tank did. From the other threads on the RU forum, it's possible it will have various 76mm guns, including possibly the S-31. The engine mentioned for it is the KV V-2K (600hp) 。The armor was supposed to be the same as the T-50 (as far as I can tell at least).

MT-25